Sunday, May 30, 2010

I don't currently have any 10G gear in networks I manage, but I've been occasionally looking at 10G products so that when I need them, I'll have a clue about what the heck is going on with that market segment.

Sunday, May 23, 2010

So, I'm starting a graduate program. It's a bit nerve-wracking since my college career was a bit ... sporadic. But the first class I'm taking is "Data Communications."

I do not expect the bulk of the subject matter to be particularly challenging. :) I'm mostly going for this as a first class to ease myself back into the routine of actually doing school work and all of that.

However, I think it will be interesting to go back to the very basic principles. It doesn't look like this will be a class where they hand me a copy of the Comer book and say "Here is some hex. Decode the packet," but still, it should be interesting to go back to looking slowly at things my brain normally glosses over and take a look at Internet connectivity with a bit of beginner's mind.

Wednesday, May 19, 2010

WTTWFTVOE (Words To The Wise From The Voice Of Experience): when attempting to set up SSH on a network device (switch, router, etc), it works a WHOLE HECK OF A LOT BETTER when you remember to actually have a domain name configured.

On a different topic, I find myself fascinated by this article from theage.com.au, which is an excerpt from The Hidden Brain. It takes a look at a couple of instances of sex bias, from people's reactions to near-identical descriptions of a person that only vary in the gender of the person described, to comparing the experiences of two transgendered academics at Stanford - one MtF and one FtM.

I think I've been fairly fortunate in avoiding some of the high levels of sexism that other women I know have experienced in the working world. Perhaps some of it is just a comparison of IT with my previous career in the construction trades. And some of it is having ended up working with and for good folks. I've certainly encountered a fair bit, but mostly it's been at a distance as far as direct "sorry, can I talk to a real engineer" and "are you the admin?" level of stuff.

On the other hand, there's this great post from Kate fuckin' Harding about women tooting their own horn and getting past that cultural expectation for women to be demure about their abilities.

Wednesday, May 12, 2010

By virtue of being the kind of network engineer I am, I'm unlikely to ever be a single-digit employee of a startup. By the time a company needs a full-time employee to handle the kind of infrastructure that I do, they're usually well into the scores of employees. And I haven't really done much of the startup thing. The smallest company I worked for was about 50 people, and even that was fairly well established.

I spent the entire late 1990's tech boom working for a single very large company. It was great fun, and I got to work on big networks and big projects. But it means that there is an entire subculture of the tech industry that I haven't really directly experienced very much -- that kind of technical nomadic thing that I've seen a bunch of friends in the SF bay and other areas go through, moving from startup to startup. (It also is one of the reasons that I've never been laid off, which feels like it makes me a huge outlier in the IT field!)

But even having avoided dealing directly with venture capital firms, I'm kind of appalled by this article in the NYT relaying some experiences an ex-HP manager type had pitching her company idea to VCs.

she recalls one venture capitalist telling her that it didn’t matter that she didn’t have business cards, because all they would say was “Mom.”

Sunday, May 9, 2010

Here's a problem I ran into. I set up a new environment with a different layer 3 infrastructure. And everything seemed to be working. Until I got reports that some people couldn't get to one network in the new environment.

So, traffic going to the range 10.2.84.0/24 was working great for some people, but for others, it was not -- TCP connections would connect and then fail after a few seconds.

I spent a bunch of time looking at switch ports, and spanning tree, looking to see where the blocking ports were and making sure that there's no loops. So I gave up on that line of inquiry and started tracing back at layer 3.

Sure enough, there were two routes for 10.2.184.0/24 in one of my core routers - one of which pointed to the right place, and one of which pointed to the wrong place.

Wednesday, May 5, 2010

Sometimes with a network capture, all you want to know is when a session starts and when it finishes. So you don't actually want to capture anything beyond the session start and finish handshakes. Here's how to do it: